Top 3 Soil pH Testers (July 2023)

Soil pH is a measure of the acidity of the soil. Soil pH has a value between 0 and 14. Values between 0 and 6.9 mean the soil is acidic and values above 7 mean the soil is alkaline. A value of 7 is neutral pH (it’s not acidic soil nor alkaline soil). Read on to learn why soil pH is important, what the pH value should be, and why it’s important to know the value accurately.

The value of soil pH determines how accessible nutrients in the soil will be to your plants. If the soil pH has a value suitable for the plants you are growing, the plants will be able to access nutrients from the soil. If the pH of your soil is not suitable, the plant will either experience nutrient deficiency or nutrient toxicity.

Most healthy garden soil should have a pH of 6.5 or close to 6.5. Soil for indoor plants (container plants) should have a pH range between 5.5 and 6.5. At that pH range, plants will be able to access all the essential nutrients from the soil.

Some exceptions are carnivorous plants, blueberries, azaleas, and rhododendrons, which require acidic soil below 5.5.

You don’t need to know the precise pH levels of your soil if you are a hobby plant grower. An approximate pH value will be sufficient. The reason for that is that most plants grow well in a wide pH range. As long as you know whether your soil is very acidic, slightly acidic, slightly alkaline, or very alkaline is good enough.

If you are a commercial grower of indoor plants, fruits, or vegetables, you need to know the precise soil pH levels, as you want to maximize your yields. Knowing the precise pH of your soil will help you adjust it if it’s not optimal. This will help your plants to absorb nutrients optimally and to achieve maximum growth.

pH measurement accuracy is also important if you plan to change the pH of your soil. pH change of 1 means an acidity change of 10, so it is easy to over-adjust your soil pH levels if you don’t start with accurate values.

pH is measured on a logarithmic scale. This means that a pH of 5 is 10 times more acidic than a pH of 6. A pH of 5 is 100 times more acidic than a pH of 7, which is a huge change.

Soil pH tester is a device used to measure pH of your soil. It can be used to test the soil pH value for both indoor and outdoor plants. There are different types of testers, some are more accurate than others and I will address their importance in the following paragraphs.

There are several types of soil pH testers: test strips, chemical tests, electronic meters (digital or analog), or professional lab tests.

Test strips and chemical tests will be accurate enough if you only want to know the approximate pH value of your garden soil or your indoor plant soil. They are the cheapest options but provide less precise results.

An electronic soil pH tester or a lab test would be your best option if you need more precise results. They would also be your best option if you are a commercial grower of indoor plants, fruits, or vegetables, and you need to maximize your yield.

The soil pH levels change over time, both for indoor and outdoor plants. Some of the factors that can change the pH value of soil are tap water, fertilizers, and other plants living in the soil (in the case of outdoor plants). To make sure the pH value is at an optimal level and that your plants can absorb nutrients optimally, you should use a soil pH meter to make sure the pH value is in the desired range.

Repotting your plants regularly (every year or so), makes soil pH testing much less needed, unless you are a commercial plant grower.

Soil pH testers can be accurate, depending on the type of tester you buy. More expensive electronic soil testers (over 100 USD) as well as lab tests are generally accurate. Less expensive testers (under 30 USD) are often not accurate, and some of them (such as test strips and chemical tests) do not provide precise results, but more general values.

The best soil pH tester is the Bluelab Soil pH pen. It’s the most accurate tester, provides instant reading, and can be used repeatedly for many years. If you want a cheaper alternative, buy Rapitest Soil Test Kit. It provides less precise measurements and can only be used 5-10 times.

Cheaper soil pH testers with a probe, such as Rapitest Digital Soil pH meter, Sonkir soil pH meter, or Fivota soil Ph meter do not always provide correct results. Meters that include a light meter, a soil moisture meter, and a pH meter in one are also generally not reliable. While you may happen to buy one that is properly calibrated and works well, in a lot of situations that won’t be the case.

The Bluelab soil pH pen is the best soil pH meter that makes soil pH measurement a breeze. It is the most accurate soil pH reader and provides an immediate reading. It is the best option for professional users, but also for hobby growers who don’t mind investing a bit of money. It requires proper maintenance in order to serve you well long term.

To use the BlueLab soil pH tester, push it in the soil with the storage cap on until it reaches the word ‘soil’ on the cap. Pull the pen out of the soil, remove the storage cap, press the “Power” button to turn on the soil tester, and place the tester back into the soil (into the previously created hole). Wait for the reading to stabilize.

Handle the probe carefully. It’s made of glass and can break if dropped. Do not force the probe into the soil.

Once you record the reading, remove the probe from soil, rinse with tap water and put back the storage cap.

Ensure the probe tip is hydrated before using. To do that, stand the pen upright and check if the probe tip is covered in liquid. If the probe tip is not covered in liquid, remove the storage cap, add a few drops of tap water to the cap, and leave the probe in for 24 hours.

After usage, it’s important to properly store the Bluelab soil pH pen in the recommended storage solution. The probe tip has to stay wet at all times.

To clean the pH soil meter, rinse it under tap water. Fill a container with tap water and add Bluelab pH Probe Cleaner or dishwashing liquid. Gently stir the probe tip in the mixture (do not hit the probe against the container walls). If the probe requires more thorough cleaning, use a soft toothbrush to gently scrub the probe. Rinse the probe under tap water to remove all detergent. Put the storage cap back on. After probe cleaning, calibration is required.

To calibrate your Bluelab pH pen, you will need two calibration solutions (pH 7.0 and pH 4.0 solutions). Make sure the pen is clean before starting calibration. Stick the probe into the pH 7.0 solution, wait until the measurement stabilizes. Once it stabilizes, press and hold the button “cal” until the display shows “CAL”. Wait a few seconds until the display shows “7.0” and the first part of calibration is over.

Rinse the probe in tap water. Stick the probe in pH 4.0 solution and repeat the process.

When you’re done rinse the probe in tap water and put back the storage cap.

The pH pen need to be calibrated as soon as it gives you a notification that it needs calibration, or after cleaning.

To see a full video on how to calibrate a Bluelab soil pH pen, watch the video below:

With proper care, you can use Rapitest Digital Soil pH meter for an unlimited amount of time.

The Luster Leaf Rapitest Soil Test Kit is an affordable and reliable option for beginners in houseplant care. It measures not only pH, but also N-P-K values, and comes with a chart of pH values for over 450 plants. However, it has limitations, offering only 5 to 10 pH tests and 5 to 10 NPK tests, takes 10 minutes for results, and provides pH readings only in the range between 4.5 and 7.5.

Add a soil sample into the narrow plastic compartment. Add powder from the capsule, add distilled water, and shake well. Wait for about 10 minutes for the soil sample to settle and the color to develop. Compare the color of the solution to the color on the plastic comparator to determine the pH levels of your soil.

To see how to use the Rapitest soil test kit check out the video below:

The Luster Leaf Rapitest Digital Soil pH meter is a digital tester that provides a fast reading (in 1 minute) and has an easy-to-read digital output. It includes a pH guide for 150 plants. However, it does not provide accurate readings for a lot of users which is why it’s not recommended.

The tester works well for some users, but a high number of users complain that the device provides the same pH value of 7.0 regardless of the medium it’s placed in. Due to the high number of unsatisfied users experiencing the same problem, this is not a device I can recommend.

Most soil pH meters in this price range have similar issues. You can also find many soil Ph testers on the market that also include a soil moisture meter or a light meter. Those types of multiple-in-one devices are generally not reliable and do not provide good measurements.

To use the Rapitest digital soil pH meter for soil testing polish the probe shaft (not the tip), water the soil, and stick the probe into the soil. Do not force the probe into the soil. Wait one minute and check the reading on the probe.

To retest, wipe away the soil from the probe and reinsert it in another pot or another part of your outdoor garden soil.

You should trust Mr. Houseplant (me) because I have been growing houseplants for over 10 years. I have been using different types of soil pH pens for over 3 years. I tested the soil of carnivorous plants as well as other indoor plants. All of this helped me learn about how to measure pH, different types of ph meters (test strips, chemical, electronic…), how to use them, how to clean them, how to calibrate them, as well as other intricacies of ph measurements.

I identified the key decision-making factors for soil pH testers and I tested 8 of the most popular testers to determine how they measure each of the factors, and to determine the best ones. The key decision-making factors were: 1) accuracy 2) ease of use 3) durability 4) price 5) unique features that set it apart from the competition 6) warranty. Continue reading for a full description of each of the decision-making factors:

Accuracy: How accurate is the soil pH tester? Does it provide accurate readings within a reasonable margin of error?

Ease of use: How easy is it to use the soil tester? Are the instructions clear and concise? Is the soil tester easy to clean?

Durability: How durable is the soil tester? Is it made from high-quality materials that will last for a long time?

Price: How much does the soil pH meter cost? Is it a good value for the price?

Unique: Unique features that set it apart from the competition

Warranty: Does the manufacturer provide a warranty? If yes, what is the duration?

Rating: Overall rating

The top-performing soil pH tester available is the Bluelab Soil pH tester, known for its unparalleled accuracy, instantaneous readings, and long-lasting usability. For a more budget-friendly option, the Rapitest Soil Test Kit is a viable alternative, although it offers slightly less precise measurements and is limited to 5-10 uses.